This patent application claims priority of Malaysian Patent Application PI 20013344 entitled xe2x80x9cExtensible Tablexe2x80x9d that was filed on 13 Jul. 2001, the disclosure of which is incorporated by reference in its entirety herein.
1. Field of the Invention
This invention relates to an extensible table that has sliding leaves, an extension leaf and a mechanism for the extension leaf to be raised and lowered vertically after the sliding leaves are moved away from each other to reveal the extension leaf.
2. Description of the Related Art
Among the many extensible tables available, some employ sliding movement to extend the tabletop. An example of an extensible table with slidable leaves is demonstrated in U.S. Pat. No. 4,297,952. This table has two leaves that can be slid away from each other for a separate third leaf to be placed in the middle of the table to form a extended tabletop. The third leaf however is detachably fixed to the table and can be easily lost. U.S. Pat. No. 4,077,335 shows a tabletop extended to twice its original length by fully sliding out two leaves from a stacked position to a side-by-side position. U.S. Pat. No. 4,718,354 shows a tabletop that is made of a flexible covering sheet with both ends being passed underneath its working plane. The flexible covering sheet is attached to a rigid panel that forms the working plane. When the table is to be extended, the ends of the table are pulled away from each other along the length of the table.
An extensible table that is extended by sliding two sliding leaves away from each other to reveal the extension leaf. The extension leaf is raised to the same level as the sliding leaves by applying an initial downward force. When the initial force is removed, the table rises by means of a raising mechanism. It is lowered by applying downward force to move the extension leaf back to its original lower level.
All the leaves are advantageously supported on a supporting frame which in turn is supported by vertical supporting members each with one end attached to the supporting frame and the other atop a horizontal floor plane. The mechanism for raising and lowering the extension leaf advantageously includes spring-loaded shafts loaded with spring and a latching means. The shafts are advantageously, attached to the supporting frame and the bottom of the extension leaf and provide the support needed and the upward force for raising the extension leaf. The latching means advantageously includes a latching pin which has one end housed in a pin housing. The pin housing is advantageously attached to the bottom of the extension leaf. The other end of the latching pin is advantageously always in the groove of a grooved block located opposite the pin housing and attached to the supporting frame. This may be achieved by having a spring in the pin housing to provide the force to hold the other end of the latching pin in the groove. The pin is advantageously bent into shape and snugly fitted in a cylindrical hollow of the pin housing. In this manner, the end of the latching pin in the said groove may advantageously move freely in the groove with respect to the end of the pin in the pin housing. The groove advantageously has a closed loop groove track with sections of varying depth. These sections may each have a constant groove depth that is different from that of the other sections or may each have varying groove depth as one traces along the entire groove. Such varying depths enable the pin, thus the extension table, to be latched at different levels as the pin moves cyclically in a given direction, clockwise or counter-clockwise.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.